Many internal combustion engines, and particularly many single cylinder internal combustion engines, employ crankcases that have a bottom side or floor that is removable from the remainder of the respective crankcase. In vertical crankshaft engines of this type, each of the top side and the bottom side of the crankcase includes a bearing for the crankshaft of the engine. The removable bottom side commonly operates as an oil pan, or collecting bin, for oil within the crankcase.
Although commonly employed, this crankcase design has certain limitations. The split line of the crankcase is between the side walls of the crankcase and its bottom side, at a low level that is often below the oil sump level and near or at the level at which oil is collecting within the crankcase. Consequently, it is not uncommon that the crankcase will leak oil along the split line. This is particularly the case as the engine ages due to normal wear and tear, or after the bottom side has repeatedly been removed and then put back onto the crankcase.
Additionally, the oil filter in such conventional crankcases is typically positioned in a low position as part of, or close to, the removable bottom side of the crankcase. This positioning of the oil filter makes it difficult to service the oil filter and, in particular, makes it difficult to service the oil filter without spilling oil. Often the designs of such oil filters is such that the mere opening of the oil filters allows oil to spill out of the oil filters. For example, many oil filters are horizontally mounted on the crankcase such that opening of an oil filter requires removing a right side portion of the oil filter from a left side portion of the oil filter. Once the seal between the right and left side portions of the oil filter is broken, oil can spill out of the oil filter. Even where the oil filters are vertically mounted on the crankcase such that opening of an oil filter requires removing a top portion of the oil filter from a bottom portion of the oil filter, the seal between the top and bottom portions is proximate the bottom edge of the oil filter (which often is along the floor of the crankcase). Consequently, opening of the oil filter requires removing the top portion even though most of the latent oil within the filter is within that top portion, and thus oil leaks from the oil filter as soon as the seal between the top and bottom portions is broken.
Further, it is common that the equipment driven by the engine is coupled to the engine (and engine crankshaft) along the bottom of the engine. Because in the above-described engines it is necessary to remove the bottom side of the engine in order to change the oil filter and/or otherwise open the engine, it also is necessary to remove the equipment on which the engine is mounted in order to perform such operations.
Additionally, conventional engines often have an electric starter mechanism that is coupled to the crankcase of the engine by way of an L-bracket or other structure. Such a manner of coupling is relatively expensive to implement insofar as a separate coupling element (e.g., the L-bracket) must be provided, and insofar as assembly of the engine requires assembling the electric starter, L-bracket and crankcase to one another.
Also, conventional engines usually employ an ignition module that provides electrical power to a spark plug of the engine. Commonly, the ignition module receives electrical energy from the relative rotation of a magnet on a flywheel (or other rotating member) of the engine with respect to a stationary magnet attached to the engine. The ignition module is typically positioned on the cylinder of the engine itself. This, however, can be disadvantageous insofar as the cylinder is typically the hottest portion of the engine during operation of the engine, which can adversely affect performance of the ignition module.
Further, conventional engines must provide lubricant to the crankshaft bearings and camshaft bearings within the engine. In vertical crankshaft engines, at least certain of these bearings are positioned proximate the top of the engine, such that oil must be communicated upward to these elements. Commonly the oil is communicated by way of channels in the crankcase, which are typically formed either by drilling or casting tubes within the crankcase. While such channels adequately deliver oil where it is needed within the crankcase, the drilling or casting of such channels is often costly to perform.
Given these various design problems associated with conventional engines, it would be advantageous if an improved engine configuration was designed that would reduce the likelihood of oil leakage from the crankcase, would facilitate the servicing of the oil filter of the engine, and would further facilitate the accessing of the interior of the engine without the removal of equipment attached to the crankshaft. Additionally, it would be advantageous if such an improved engine design also facilitated the mounting of a starter on the engine, reduced the amount of heat experienced by the ignition module of the engine, and could be implemented to include oil channels without requiring expensive drilling or casting processes to form those channels.